Porous carbon adsorbent from cellulose acetate for efficient Hg0 adsorption from coal-fired flue gas

Abstract

The elemental mercury emitted from coal flue gas has caused serious harm to the ecological environment, and the development of high efficiency Hg⁰ adsorbents has been a research hotspot. In this study, cellulose acetate derived carbon adsorbent was prepared by the combination of soft template and activation method, which realized the efficient removal of Hg⁰ from coal flue gas. The mechanism of adsorption process was studied by FTIR, Hg-TPD and kinetic simulation. The results show that the soft template agent mainly constructed mesopores in the adsorbent, and the activator mainly constructed micropores. The synergistic effect of the two significantly enhanced the physical adsorption of Hg⁰ by the adsorbent. In addition, cellulose acetate with high O/C (0.93) was used as a carbon source to promote the formation of a large number of C = O functional groups on the surface of the adsorbent, which is the main chemisorption site of Hg⁰. The adsorbent has a high mercury adsorption capacity, reached 3,800 μg/g.